DE2832405A1 - METHOD FOR PRODUCING GLYOXAL FROM AETHYLENE GLYCOL - Google Patents

Description

BASF Aktiengesellschaft "X" ^αζ · ^c ° 50 / O333l6

Process for the production of glyoxal from ethylene glycol ⁿ

From the US Patents 2,339,282 and 2,339,346 to 2,339,348 is known that can be made of ethylene glycol by the vapor phase oxidation in the presence of oxygen to catalysts based on copper or copper oxide at temperatures of 225 to 45O ⁰ C glyoxal. If germanium, tin, lead, nitrogen, phosphorus, arsenic, antimony or bismuth are added to the copper-containing catalysts in accordance with the information in DT-OS 1 923 048, glycol yields of up to 72 % are achieved. According to the method of DT-OS 2,634,439, bromine compounds are added to the gaseous mixture.

A considerable disadvantage of these known processes arises from the fact that the catalysts age relatively quickly, so that the yield immediately drops. It was found that the glyoxal yield when using copper turnings as a catalyst at 310 ^° C. and continuous operation drops from approx. 68 to approx. 59 % after a running time of 73 hours. If a catalyst described in DT-OS 1 923 is used for the oxidation of ethylene glycol to glyoxal, according to the information in DT-OS 2 158 343, the catalyst selectivity falls from an initial value of 60 to 64 % to 55 % over a 700-hour operating time. . From DT-OS 2 158 344 it emerges that after 18 days of operation the selectivity of one in the DT-OS

030007/0025

28324Q5

BASF Aktiengesellschaft - 3 ~ O.Z. OO5O / O33316

1 923 048 described catalyst has dropped ^{from an initial 58 to Ί} 54 %. In order to regenerate copper-containing catalysts, it has been proposed to treat them either oxidizing or reducing with interruption of the normal mode of operation. According to the DT-OS 2158343, a Cu-Ag-P catalyst is regenerated after 700 hours running time by a 12-hour reduction at 45O ⁰ C. DT-OS 2 158 344 describes the regeneration of a Cu-P catalyst after an operating time of 18 days, during which at least 1 day of excess oxygen is passed over the catalyst.

These regeneration processes have the disadvantage that they with production downtime and require extensive safety measures to prevent the mixing of the To exclude regenerating air used with the reaction gas.

It has now been found that in the production of GIyoxal by vapor phase oxidation of ethylene glycol with an oxygen containing gas in the presence of copper containing oxidation catalysts at elevated temperature significantly extend the life of the catalysts can if you have the vapor phase oxidation in the presence a phosphorus compound which is volatile under the reaction conditions carries out, the amount of phosphorus (calculated P), based on the amount by weight of ethylene glycol, 1 to Is 100 ppm.

Surprisingly, phosphorus only unfolds in the form of the under Compounds that are volatile under the reaction conditions have this advantageous effect, even very small amounts of P being sufficient. The amount of phosphorus (calculated P), based on the amount by weight of ethylene glycol, is preferably 2 to 25 ppm.

030007/0025

BASF Aktiengesellschaft -4- O. Z. 0050/033316

It is advisable to choose those phosphorus ^{compounds which η have} a boiling point similar to that of ethylene glycol. Suitable phosphorus compounds are, for example, trimethyl phosphate, triethyl phosphate, tri-iso-propyl phosphate, tri-n-propyl phosphate, trimethyl phosphite, trietyhlphosphite, triethylphosphine oxide, methylphosphonic acid diethyl ester, methylphosphonic acid dimethyl ester or ethylphosphonic acid diethyl ester.

The vapor phase oxidation of ethylene glycol with the oxygen-containing gas to the copper-containing catalysts is carried out in per se known manner, for example at temperatures at about 225 ° to about 500 ⁰ C, by. Contained as copper. Tending catalysts are, for example, metallic copper, copper-containing alloys or compounds with metals or non-metals, such as copper phosphides, copper bronzes or alloys of copper with silver and / or gold, copper ores such as malachite and copper compounds, which can be completely or partially reduced to copper during the reaction such as copper (I) oxide, copper (II) oxide, and compounds that convert to copper oxides when heated, such as copper nitrate and copper acetate. Copper phosphate and copper antimonate are also suitable. Other metal or non-metal oxides such as the oxides of zinc, chromium, phosphorus, antimony, tin and bismuth can also be added to the copper-containing compounds. The copper-containing catalytic composition can also be applied to an inert support or, if appropriate, can be diluted with an inert material. If appropriate, the catalyst can also be subjected to a reducing treatment before it is used.

Copper-containing catalysts which do not have a large internal surface area, for example those with a Surface of less than 50 m per g. Special technical Metallic copper and alloys that

030007/0025

BASF Aktiengesellschaft - 5 - O. Z. 0050/033316

Contain copper as an essential component * They are used, for example, in the form of turnings. Wire meshes, gauzes or as supported catalysts with, for example, an inert carrier with little surface area.
5

The process is carried out, for example, so that a gaseous mixture of ethylene glycol and water (water content 0.1 to 99 %) together with oxygen in an amount between about 0.5 and 2.0 mol, based on 1 mol of ethylene used IQ glycol, possibly together with nitrogen (0 to 99 volume # of the total gas mixture) passes over the ^{catalyst kept at 225 to 500 0} C, the volatile phosphorus compound being added to the gaseous starting mixture beforehand. The gaseous product mixture leaving the reactor is washed out with water as usual.

Example 1 ■

25.25 parts of copper turnings are installed in a tubular reactor 20 made of V2A steel with an inner tube diameter of 21 mm in such a way that the catalyst filling height is 18 cm. A gaseous mixture of 6.38 parts by weight of ethylene glycol, 2.04 parts by weight of water, 0.00019 parts by weight of trimethyl phosphate (CH, O), PO (that is 6.58 ppm of P, based on the ethylene glycol weight), 3465 parts by volume is passed in continuously per hour oxygen and I88 000 parts by volume of nitrogen over the maintained at a temperature of 300 ⁰ C catalyst. The product mixture is washed out of the gas stream leaving the reactor with water. On the basis of the analysis of the aqueous solution obtained, the following result is obtained:

Amount of ethylene glycol used = 421.0 parts by weight of aqueous product solution = 18.18.5 parts by weight

030007/0025

BASF Aktiengesellschaft - 6 - O. Z. 0050/033316

Product-containing solution (determined by titrimetry): ^Ί 14.5% by weight of glyoxal = 263.7 parts.

(corresponds to a glyoxal yield, based on the ethylene glycol used, of 67j0 % of theory)

After a further, uninterrupted running time of 96 hours, the following results are obtained: 10 Amount of ethylene glycol used = ^ 5.32 parts Aqueous product solution = 537.99 parts

The product solution contains: 15th

i », 74 wt. Glyoxal = 25.50 parts

(corresponds to a glyoxal yield, based on the ethylene glycol used, of 60.2 % of theory) 20 comparative example (no addition of a volatile

P connection)

The procedure is as described in Example 1 to obtain here ₂ c per hour, a gaseous mixture of 6.56 parts by weight ethylene glycol, 2.10 parts by weight water, 3570 parts by volume of oxygen and I88 000 parts by volume of nitrogen over the maintained at a temperature of 310 ⁰ C catalyst passes .

The following result is obtained:

Amount of ethylene glycol used = 32.01 parts by weight

Aqueous product solution = 360.42 parts by weight

030007/0025

BASF Aktiengesellschaft. -7- O.Z. 0050/053316

The product solution contains ⁿ

5. -61 parts by weight of glyoxal = 20.22 parts

.5 (corresponds to a glyoxal yield, based on the ethylene glycol used, of 67.6 % of theory)

After a further, uninterrupted running time of 73 hours, the following results are obtained: 10

Amount of ethylene glycol used = 40.41 parts. Aqueous product solution = 451.72 parts

The product solution contains:
15th

4.90 wt .- * glyoxal. = 22.13 parts

(corresponds to a glyoxal _{yield a,} based on the ethylene glycol used, of 58.6 % of theory) 20

Example 2

In a tubular reactor charged with copper turnings as described in Example 1, a gaseous mixture of 6.53 parts of ethylene glycol, 2.08 parts of water, 0.000 389 parts of trimethyl phosphate (CHJD), PO (that is 13.2 ppm of P) is continuously supplied per hour directed to the Äthylenglykolgewicht), 3465 parts by volume of oxygen and 188 000 parts by volume of nitrogen over the held at 310 ⁰ C catalyst. The gas stream leaving the reactor is worked up as described in Example 1. The following result is obtained:

Amount of ethylene glycol used = 38.84 parts. Aqueous product solution = 560.33 parts

030007/0025

BASF Aktiengesellschaft - 8 - O. Z. 0050/033316

The product solution contains ^Ί

4.40 wt. Glyoxal = 24.65 parts

(corresponds to a glyoxal yield, based on the ethylene glycol used, of 67.9 % of theory)

After another uninterrupted term of 1 I66 Hours the following result will be obtained: 10

Amount of ethylene glycol used = 37.43 parts Aqueous product solution = 508.86 parts

The product solution contains
15th

4.46 wt % glyoxal = 22.70 parts

(corresponds to a glyoxal yield, based on the ethylene glycol used, of 64.8 % of theory) 20

Comparative example (too much volatile P compound)

In a tubular reactor charged with copper turnings as described in Example 1, there is continuous per hour a gaseous mixture of 6.19 parts of ethylene glycol, 1.97 parts of water, 0.00367 parts of trimethy! phosphate (ΟΗ, Ο), ΡΟ (That is 131 ppm P, based on the ethylene glycol weight), 2,645 parts by volume of oxygen and 185,000 parts by volume Nitrogen passed over the catalyst kept at 300 ° C. The gas flow leaving the reactor is operated as described in Example 1, giving the following result receives:

Amount of ethylene glycol used = 37.63 parts. Aqueous product solution = 461.64 parts

030007/0025

BASF Aktiengesellschaft - 9 - O. Z. 0050/033316

The product solution contains: ^Ί

5.20 wt % glyoxal = .24.01 parts

(corresponds to a glyoxal yield, based on the ethylene glycol used, of 68.2 % of theory)

After a further, uninterrupted running time of 48 hours, the following result is obtained:
10

Amount of ethylene glycol used = 37.02 parts by weight

Aqueous product solution = 543.71 parts by weight

The product solution contains:

3.49 wt % glyoxal = 18.98 parts

(corresponds to a glyoxal yield based on the ethylene glycol used of 53.9 % of theory) 20

Comparative example1 (P alone in contact)

A mixture of copper powder and antimony phosphate (SbPO ^) is applied by flame spraying to steatite balls with a rough surface of 6 mm in diameter. The one made in this way The catalyst contains approx. 16 g of active mass of the composition 88.6 percent by weight Cu per liter of support; 0.5 percent by weight Sb and 0.097 percent by weight P. 63.03 parts of this catalyst are constructed from V2A steel Built-in tubular reactor with an inner diameter of 21 mm. A gaseous mixture is continuously produced every hour 6.75 parts of ethylene glycol, 2.16 parts of water, 2940 parts by volume Oxygen and 186,000 parts by volume of nitrogen passed over the catalyst kept at 325 ° C. That Product mixture is released from the gas leaving the reactor

030O07 / 002S

BASF Aktiengesellschaft - 10 - O.Z. 0050/033316

Washed out the stream with water, and the ^aqueous solution thus obtained was analyzed after the end of the balance.

The following result is obtained:

Amount of ethylene glycol used = 122.31 parts. Aqueous product solution = 969.64 parts

The product solution contains:

7.89 wt % glyoxal = 76.50 parts

(corresponds to a glyoxal yield, based on the ethylene glycol used, of 66.9 % of theory)

After a further, uninterrupted running time of 48 hours, the following results are obtained:

Amount of ethylene glycol used = 124.52 parts. Aqueous product solution = 965.78 parts

The product solution contains:

7.01 wt % glyoxal = 67.70 parts

(corresponds to a glyoxal yield, based on the ethylene glycol used, of 58.1 % of theory)

Example 3

In accordance with the preceding comparative example, a catalyst is produced by flame spraying. This catalyst contains approx. 179 g of active mass of the composition 90.2 percent by weight Cu per liter of steatite carrier; 0.8 weight

percent Sb and 0.08 percent by weight P. 65.92 parts of the cata-

030007/0025

BASF Aktiengesellschaft - 11 - O. Z. 0050/033316

lysators are installed in a tubular ^{reactor 3} constructed from V2A steel with an inner diameter of 21 mm. A gaseous mixture of 6.58 parts of ethylene glycol, 2.10 parts of water, 0.000196 parts of trimethyl phosphate, (CH ₅ O) ₃ PO (that is 6.59 ppm of P, based on the ethylene glycol weight), 3570 is now continuously produced every hour Parts by volume of oxygen and 188,500 parts by volume of nitrogen passed over the catalyst kept at 335 ° C. The product mixture is washed out with water from the gas stream leaving the reactor, and the aqueous solution thus obtained is analyzed after the end of the balance.

The following results are obtained:

Amount of ethylene glycol used = 11.8.16 parts Aqueous product solution = 439.71 parts

The product solution contains:
17.44 wt. Si glyoxal = 76.69 parts

(corresponding to a yield of glyoxal, based on ethylene glycol, of 69, 4% of theory)

After another, almost uninterrupted running time of 2654 hours the following results are obtained:

Amount of ethylene glycol used = 37.20 parts Aqueous product solution = 519.97 parts

The product solution contains:

4.46 wt% glyoxal = 23.19 parts

030007/0025

BASF Aktiengesellschaft - 12 - O. Z. 0050/033316

'{corresponds to a glyoxal yield, based on ¹ ethylene glycol used, of 66.7 % of theory)

Example 4

63.07 parts of the catalyst described in Example 3 are installed in a tubular reactor constructed of V2A steel with an internal diameter of 21 mm. A gaseous mixture of 6.65 parts of ethylene glycol, 2.12 parts of water, 0.000396 parts of trimethyl phosphate (CH, 0), PO (that is 13.2 ppm of P, based on the ethylene glycol weight), 3250 parts by volume of oxygen is now continuously produced every hour and 187,000 parts by volume of nitrogen passed over the catalyst kept ^{at 335 ° C.} The product mixture is washed with water from the gas stream leaving the reactor, and the aqueous solution thus obtained is analyzed after the end of the balance.

The following result is obtained:
20th

Amount of ethylene glycol used = 40.3.9 parts of aqueous product solution = 426.65 parts

The product solution contains:
25th

5.95 wt % glyoxal = 25.39 parts

(corresponds to a glyoxal yield, based on the ethylene glycol used, of 67.2 % of theory) 30

After a further, uninterrupted running time of 42 8 hours the following result is obtained:

Amount of ethylene glycol used = 39.61 parts. Aqueous product solution = 420.32 parts

030007/0025

BASF Aktiengesellschaft -13- O. Z. 0050/033316

The product solution contains: ^Ί

5.44 wt. 2 glyoxal = 22.87 parts

(corresponds to a glyoxal yield, based on the ethylene glycol used, of 61.7 % of theory)

Example 5

65.66 parts of the catalyst described in Example 3 are built into a tubular reactor made of V2A steel with an inner diameter of 21 mm. Becomes continuous now every hour a gaseous mixture of 6.47 parts of ethylene glycol, 2.06 parts of water, 0.000771 parts of trimethyl phosphate (CH.-0), P0 (that's 26.3 ppm P based on the Ethylene glycol weight), 3250 parts by volume of oxygen and 187,000 parts by volume of nitrogen passed over the catalyst kept at 335 ° C. The product mixture is off the gas stream leaving the reactor was washed out with water, and the aqueous solution thus obtained after the end of the balance analyzed.

The following result is obtained:

Amount of ethylene glycol used = 39.39 parts Aqueous product solution = 398.7 parts

The product solution contains:
6.13 wt % glyoxal * = 24.44 parts

(corresponds to a glyoxal yield, based on the ethylene glycol used, of 66.4 % of theory)

L -i

030007/0025

BASF Aktiengesellschaft - 14 - O. Z. 0050/033316

Räch a further continuous period of 221 · ³ stun the following result is obtained:

Amount of ethylene glycol used = 40.67 parts Aqueous product solution = 409.41 parts

The product solution contains:

5.52 wt % glyoxal = 22.60 parts

(corresponds to a glyoxal yield, based on the ethylene glycol used, of 59.4 % of theory)

Example 6

64.7 parts of the catalyst described in Example 3 are installed in a tubular reactor constructed of V2A steel with an internal diameter of 21 mm. A gaseous mixture of 6.90 parts of ethylene glycol, 2.20 parts of water, 0.00206 parts of trimethyl phosphate (CH, O), PO (that is 66 ppm P, based on the ethylene glycol weight, 3250 parts by volume of oxygen and 177,000 parts by volume) is continuously produced every hour Nitrogen passed over the catalyst kept at 335 ° C. The product mixture is washed with water from the gas stream leaving the reactor, and the aqueous solution thus obtained is analyzed after the end of the balance.

The following result is obtained:

Amount of ethylene glycol used = 4 l, 37 parts of aqueous product solution = 487.07 parts

The product solution contains:
5.28 wt% glyoxal = 25.72 parts

030007/0025

BASF Aktiengesellschaft - 15 - O. Z. 0050/033316

^ corresponds to a glyoxal yield, based on " ¹ ethylene glycol used, of 66.5 % of theory)

After another, uninterrupted running time of 48 hours-5 you get the following result:

Amount of ethylene glycol used = 124.87 parts. Aqueous product solution = 1110.88 parts

10 The product solution contains:

6.34 wt % glyoxal = 70.34 parts

(corresponds to a glyoxal yield, based on the ethylene glycol used, of 60.3 % of theory)

030007/0025

Claims (4)

BASF Aktiengesellschaft O.Z. 0050/033316 Claims ^Ί Process for the production of glyoxal by vapor phase oxidation of ethylene glycol with an oxygen-containing gas in the presence of copper-containing oxidation catalysts at elevated temperature, characterized in that the vapor phase oxidation is carried out in the presence of a phosphorus compound which is volatile under the reaction conditions, the amount of phosphorus (calculated P) being based on .the amount by weight of ethylene glycol, 1 to 100 ppm. 2. The method according to claim 1, characterized in that the phosphorus compound which is volatile under the reaction conditions is added to the ethylene glycol to be supplied to the vapor phase oxidation. 3. Method according to claim 1, characterized in that the amount of phosphorus (calculated P) based on the amount by weight of ethylene glycol is 2 to 25 ppm. 4. The method according to claim 1, characterized in that the phosphorus compound which is volatile under the reaction conditions is trimethyl phosphate, triethyl phosphate, tri-isopropyl phosphate, tri-n-propyl phosphate, trimethyl phosphite, triethyl phosphite, triethyl phosphine oxide, methyl phosphonic acid diethyl ester, methyl phosphonic acid dimethyl ester, methyl phosphonic acid dimethyl ester. 466/78 Hee / ro 07/21/1978 ORfGiNAL INSPECTED 030007/0025